To lag in the fight at the very outset of the struggle and thereby to furnish proof of our coming defeat is a very hateful and dangerous thing. A firm beginning will certainly be useful for us when we later grow slack. A soul that is strong at first but then relaxes is spurred on by the memory of its former zeal. And in this way new wings are often obtained.
When the soul betrays itself and loses the blessed and longed for fervour, let it carefully investigate the reason for losing this. And let it arm itself with all its longing and zeal against whatever has caused this. For the former fervour can return only through the same door through which it was lost.
[John Climacus, Ladder of Divine Ascent]